We are continuing studies of cellular complex polysaccharides from normal and transformed BALB/c cells. Our system includes a variety of spontaneously transformed cells, causing tumors which are either malignant or regressive when injected into immunocompetant BALB/c mice. Glycosyl transferases are determined using whole cells incubated with nucleotide sugars under conditions where there is no nucleotide sugar uptake or degradation. Ectoglycosyltransferases detected under these conditions are being studied to determine their role in cellular interactions. We are concentrating our efforts on the ability of cells to catalyze synthesis on mannosyl isoprenol lipid intermediates. We feel that understanding why cells can catalyze the transfer at the cell surface of sugars to intermediate in complex polysaccharide synthesis offers a chance for insight into the biology of both complex saccharide synthesis and cellular interactions. We are also conducting studies of cell surface glycoproteins and glycolipids. We have isolated three major classes of glycoproteins from cells, and are conducting detailed chemical studies of glycopeptides prepared from pronase digests of each glycoprotein class. Our goal is to learn detailed chemical structures of cell surface complex polysaccharides of normal and transformed cells. BIBLIOGRAPHIC REFERENCES: Patt, L., Endres, R., Lucas, D., and Grimes, W. Ectogalactosyltransferase Studies in Fibroblasts and Concanavalin A - stimulated Lymphocytes. J. Cell Biol. 68, 799 (1976). Grimes, W., Patt, L., and Greegor, S. Complex Polysaccharides of Normal and Transformed Cells in Nutritional Requirements of Animal Cells, R. Ham. Ed. l976, in press.